US4487842AExpiredUtility

Low-loss microwave dielectric material

64
Assignee: JAPAN BROADCASTING CORPPriority: May 26, 1982Filed: May 18, 1983Granted: Dec 11, 1984
Est. expiryMay 26, 2002(expired)· nominal 20-yr term from priority
Inventors:Shoichiro NomuraYoshihiro Konishi
C04B 35/495H01G 4/1254H10N 30/853
64
PatentIndex Score
21
Cited by
11
References
17
Claims

Abstract

A low-loss microwave dielectric material comprising a sinter of a mixture of a perovskite type structure compound oxide comprising singly or mainly Ba(Zn1/3Ta2/3)O3 and Ba(Mg1/3Ta2/3)O3 with a small amount of Mn. Mn addition not only favorably affects sinterability to lower the required sintering temperature but also advantageously heightens the unloaded Q factor of the resulting sinter in an SHF band.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
       1. A low-loss microwave dielectric ceramic consisting essentially of a sinter of a mixture of a perovskite type structure compound oxide having a porosity in the range of 1 to 3% consisting essentially solely or mainly of at least one member selected from the group consisting of Ba(Zn 1/3  Ta 2/3 )O 3  and Ba(Mg 1/3  Ta 2/3 )O 3  with Mn having an amount within the range of 0.5-5 mol %. 
     
     
       2. A low-loss microwave dielectric ceramic as claimed in claim 1, wherein the amount of Mn is within the range of 0.5-2 mol %. 
     
     
       3. A low-loss microwave dielectric ceramic as claimed in claim 1, wherein said perovskite type structure compound oxide further contains less than 25 mol % of at least one member selected from the group consisting of Ba(Zn 1/3  Nb 2/3 )O 3  and Ba(Mg 1/3  Nb 2/3 )O 3 . 
     
     
       4. A low-loss microwave dielectric ceramic as claimed in claim 1, wherein said sinter is one prepared in a sintering atmosphere of at least one member selected from the group consisting of nitrogen and air. 
     
     
       5. A low-loss microwave dielectric ceramic as claimed in claim 3, wherein said sinter is one prepared in a sintering atmosphere of at least one member selected from the group consisting of nitrogen and air. 
     
     
       6. A low-loss microwave dielectric ceramic as claimed in claim 1, wherein said Mn is obtained from at least one member selected from the group consisting of manganese oxides and manganese carbonates. 
     
     
       7. A low-loss microwave dielectric ceramic as claimed in claim 3, wherein said Mn is obtained from at least one member selected from the group consisting of manganese oxides and manganese carbonates. 
     
     
       8. A low-loss microwave dielectric ceramic as claimed in claim 1, wherein said perovskite type structure compound oxide is a calcined powder mixed with said small amount of Mn derived from an aqueous treating solution of MnSO 4 .4H 2  O. 
     
     
       9. A low-loss microwave dielectric ceramic as claimed in claim 3, wherein said perovskite type structure compound oxide is a calcined powder mixed with said small amount of Mn derived from an aqueous treating solution of MnSO 4 .4H 2  O. 
     
     
       10. A process for preparing a low-loss microwave dielectric ceramic comprising the steps of: (1) adding a small amount from 0.5 to 5 mol % of Mn to a perovskite type structure compound oxide powder consisting essentially singly or mainly of at least one member selected from the group consisting of Ba(Zn 1/3  Ta 2/3 )O 3  and Ba(Mg 1/3  Ta 2/3 )O 3     (2) calcining the resultant mixture under a temperature within a range of 1200°-1400° C. to form Mn-treated oxide powder, and   (3) sintering said Mn-treated oxide powder at a temperature within a range of 1550°-1600° C. for 1-3 hours.   
     
     
       11. A process as claimed in claim 10, wherein said perovskite type structure compound oxide powder further comprises less than 25 mol % of at least one member selected from the group consisting of Ba(Zn 1/3  Nb 2/3 )O 3  and Ba(Mg 1/3  Nb 2/3 )O 3 . 
     
     
       12. A process as claimed in claim 10, wherein said sintering is carried out in a sintering atmosphere of at least one member selected from the group consisting of nitrogen and air. 
     
     
       13. A process as claimed in claim 11, wherein said sintering is carried out in a sintering atmosphere of at least one member selected from the group consisting of nitrogen and air. 
     
     
       14. A process as claimed in claim 10, wherein said small amount of Mn is obtained from at least one member selected from the group consisting of manganese oxides and manganese carbonates. 
     
     
       15. A process as claimed in claim 11, wherein said small amount of Mn is obtained from at least one member selected from the group consisting of manganese oxides and manganese carbonates. 
     
     
       16. A process as claimed in claim 10, wherein said perovskite type structure compound oxide is a calcined powder, and wherein said small amount of Mn is added to said perovskite type structure compound oxide by treating said calcined powder with an aqueous treating solution of MnSO 4 .4H 2  O. 
     
     
       17. A process as claimed in claim 11, wherein said perovskite type structure compound oxide is a calcined powder, and wherein said small amount of Mn is added to said perovskite type structure compound oxide by treating said calcined powder with an aqueous treating solution of MnSO 4 .4H 2  O.

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